苏州古城区水体污染时空分异特征及污染源解析

利用2012年苏州古城区30个监测断面的11个水质指标数据,综合运用水质指数模型(WQI)、层次聚类(HCA)、后退式判别(DA)、因子分析(FA)、绝对主成分多元线性回归(APCS-MLR)及GIS平台系统分析了旅游城市苏州古城区河网水体污染物时空分异特征及污染源解析.结果表明:①苏州古城区内城河及外围河道水体的CCME WQI值介于40~74之间,其中,66.67%的监测点水环境遭到严重破坏,主要集中在内城河河道;②系统聚类分析将采样时间分为1—3月、11月及4—6月、7—10月3个时段;将采样点分为2类,从空间上反映了古城区内城河与外围河道的污染程度;③采样时间和采样点聚类分析结果的判别分析交叉验证,正确率分别达到88.1%和78.5%;表征时间差异性用了7个指标,分别为总氮(TN)、总磷(TP)、溶解氧(DO)、水温(T)、高锰酸盐指数(COD Mn)、藻密度(Algae density)、叶绿素(Chl),表征空间差异性用了5个指标,分别为总氮(TN)、氨氮(NH3-N)、溶解氧(DO)、浊度(Turb)、水温(T);显著性指标的时空差异性比较明显;④古城区内城河河道在1—3月、11月及4—6月、7—10月3个时段内的因子分析分别提取4、3和4个因子,累积解释方差分别为83.64%、72.67%和77.98%;古城区外围河道在全年内的因子分析提取了3个因子,累积解释了62.28%的总方差;因子分析表明,古城区内城河及外围河道主要为氮、磷等营养物质污染及夏季藻类爆发的问题,与古城区外围河道相比内城河河道的污染更为严重,应优先开展治理;内城河氮、磷污染除了有来自生活、餐饮旅游等第三产业的污染外,还受到降雨地表径流及河道底泥释放的非点源污染影响;⑤绝对主成分多元线性回归(APCS-MLR)表明,总氮(TN)、氨氮(NH3-N)、总磷(TP)和高锰酸盐指数(COD Mn)主要来自城市生活及餐饮旅游等第三产业污水.研究结果可为苏州古城区河道水环境改善治理提供参考.     

湖库富营养化指标的高频监测方法研究

湖泊和水库中蓝藻水华等富营养化灾害的形成往往只需几天的时间,因此,在富营养化水体的水质管理上需要进行高频的水质指标监测.本研究以新安江水库(千岛湖)为例,基于水质传感器探头现场获取的水质参数,采用多元逐步回归分析方法,获得总氮(TN)、总磷(TP)、高锰酸盐指数(CODMn)、叶绿素a(Chl)、营养状态指数(TSI)、透明度(SD)等指示湖库富营养化状况的关键水质指标与水体藻蓝素(PC)、浊度(TURB)、有色可溶性有机物(CDOM)、电导率(EC)、溶解氧(DO)等现场水质参数之间的定量关系,以满足高频监测湖泊富营养化关键指标的需要.结果表明,2013年调查期间,新安江水库各湖区水质差异较大,调查的54个点位中,SD介于1.10~8.60 m之间,TN介于0.78~1.68mg·L-1之间,TP介于7.90~71.1μg·L-1之间,具有较为宽泛的代表性.相关分析表明,CDOM与TN、TP、CODMn、Chl、TSI、SD均存在显著的相关关系,可以作为新安江水库水质富营养化状况的一个重要自动监测指标;TURB与TP、Chl、SD、TSI之间也显著相关,PC则与TN、CODMn相关,而探头获得的叶绿素浓度值(Chls)与TN、SD显著负相关.通过与实测值比较表明,统计分析建立的富营养化指标多元回归方程估算值与实测值吻合度较高,能够满足水体管理的需要.本研究为湖泊和水库的富营养化灾害监控、预警提供了理论依据.     

基于多因素灰色预测模型的生活污水量预测研究

生活污水作为城市水环境的主要污染源,进行生活污水排放量的预测是十分必要的.污水排放量预测方法有多种,不同的方法有各自不同的特点.为提高预测精度,采用灰色预测与多元线性回归相结合的方法,综合各种因素建立多因素灰色预测模型.并以人口和人均纯收入作为影响因素,将该模型应用于苏州横泾街道生活污水排放量的趋势预测中.结果表明：该模型能反映系统的实际情况,建模精度高,平均相对误差只有0.069 8％,值得在污水排放预测中推广应用.     

哈尔滨市AQI与空气污染物的相关分析研究

空气质量问题已成为民众关注的热点问题.选取哈尔滨市2014年-2015年AQI日报数据,分别分析了供暖期和非供暖期PM2.5、PM10、CO、SO2、NO2、O3六种主要空气污染物与AQI的相关性,结果表明,AQI与6个主要污染物间呈显著性相关.同时建立了供暖期和非供暖期AQI与主要空气污染物的多元线性回归模型,结果表明,CO对AQI起着主要作用.因此,提高供暖过程中煤炭燃烧效率,可有效削减空气中CO的浓度,对于改善空气质量起着至关重要的作用.     

旅游地农户生计资本评估与生计策略选择——以海螺沟景区为例

旅游地可持续发展需要重点关注当地居民生计的可持续。以海螺沟景区为案例地,基于可持续生计框架构建了适用的生计资本评估指标体系,量化识别了景区农户可持续的生计方式,明确了影响两类脆弱性农户生计策略选择的主要因素。结果表明：在研究区六种生计方式中,采用均衡兼收型和旅游主营型策略的农户其生计资本水平最高,而传统务农型和务工型农户生计资本水平最低。不同生计策略类型的农户在空间上集聚分布。缺乏金融资本是影响传统务农型和务工型农户选择均衡兼收型生计策略的主要因素,而物质资本和社会资本的缺乏则对他们选择旅游主营型生计策略有显著的影响。此外,海拔、距公路和核心景点的距离也对农户生计策略的选择有重要影响。     

COMPUTER-AIDED PLANNING FOR MULTIPLE-PURPOSE RESERVOIR OPERATING POLICIES1

ABSTRACT: Computer-aided planning (CAP) for multiple-purpose reservoir operations involves use of state-of-the-art simulation and optimization methods, color graphic displays, and interactive computing interfaces. These technologies were integrated into a coherent system that has user-friendly interfaces to help the process of communicating reservoir system operations, solicit planning participant preferences and valuation judgments, and provide understandable feedback of system performance. The CAP system was imbedded in a comprehensive public involvement program that paralleled the reservoir operating policy modeling process, as part of multipurpose reservoir operations planning on the Great Plains Reservoirs in Colorado. Experience with the approach indicates the involved publics can quickly learn of reservoir system limitations and opportunities, and can indeed participate in the operations planning process.     

Public Preference for Endemism over Other Conservation-Related Species Attributes

Abstract:  Public preferences are likely to play an important role in prioritizing species at risk for conservation. We conducted a survey of British Columbians (Canada) ( n = 555 , r = 73 % ) to examine how the public ranks a species' attributes (rather than named species) with respect to conservation priority. Endemism, defined as species only or mainly occurring in British Columbia or species occurring in British Columbia and nowhere else in Canada, was considered the most important among the measured attributes. This preference was strongest among men and among respondents who had completed postsecondary education. The preference for endemism is generally consistent with science-based federal listings of British Columbian species. This congruence between listing and public opinion is welcome if such congruence is considered important. We suggest that investigating how much the public values species' attributes, as opposed to named species, provides a more efficient way of incorporating public opinion into policies on species at risk, especially if large numbers of species must be ranked for conservation priority .     

Ambient Ultraviolet B Radiation and Prevalence of Infection by Batrachochytrium dendrobatidis in Two Amphibian Species

Abstract: Chytridiomycosis, the emerging disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd) is responsible for declines and extirpations of amphibian populations worldwide. Environmental covariates modify the host‐Bd interaction and thus affect the ongoing spread of the pathogen. One such covariate may be the intensity of ultraviolet B (UV‐B) radiation. In a field experiment conducted in Laguna Grande de Peñalara (central Spain), a mountainous region where the presence of Bd has been documented since 1997, we analyzed the potential effect of environmental UV‐B (daily maximum 2.5–3.9 W/m²) on the susceptibility of larvae of the common toad (Bufo bufo) to Bd. The proportion of infected individuals increased as tadpoles developed. The prevalence of Bd was significantly lower in tadpoles exposed to environmental UV‐B intensities (2.94%) than in tadpoles not exposed to the radiation (9.72%). This finding mirrors that seen for a second amphibian species, the European midwife toad (Alytes obstetricans), for which conditional prevalence (i.e., prevalence of infection conditioned on the probability of a site being infected) across the Iberian Peninsula was inversely correlated with the intensity of UV‐B.